I. Field of the Invention
This invention relates to a switch which closes an electric circuit to operate a load for a predetermined period of time in response to a sound.
More particularly, the present invention relates to a switch comprising in combination a diaphragm for receiving a sound, a piezo-electric element operated by the diaphragm, an amplifying circuit, a monostable vibrator circuit, and a load actuating circuit.
II. Description of the Prior Art
Up to the present time, there has been a need for electrically driven toys or lighting equipment to work for a predetermined period of time in response to an audible sound.
There has also been a need to produce such equipment at low cost, as well as equipment assemblies durable in construction and reliable in operation.
Various electric circuits are usually incorporated to operate sound responsive equipment. Particularly, transistors or transistor circuits are used in order to meet the demand for compactness of the equipment, and accordingly, moisture or even a speck of dust must be completely excluded to allow reliable operation.
The present invention comprises a household lighting device which works only for a certain period of time, and lights a lamp for about five seconds in response to a sound such as the sound produced by the clapping of hands.
The device has also been provided with an input inhibit circuit to prevent reactivation of the switch by an extraneous sound during the predetermined time period.